Vibration damping system for drilling equipment

Abstract

A downhole tool is described designed to be suspended from a surface location into a wellbore ( 11 ), the tool including at least one module ( 20 ) with elements susceptible to mechanical vibrations or shocks, having the module coupled to remaining parts of the tool with one or more transducers ( 31 ) comprising electroactive polymeric material.

1 . A downhole tool designed to be suspended from a surface location into a wellbore, said tool including at least one module with elements susceptible to mechanical vibrations or shocks, wherein said module is coupled to remaining parts of the tool with one or more transducers comprising electroactive polymeric material. 
   
   
       2 . The tool of  claim 1 , being a logging-while-drilling or measurement-while-drilling tool. 
   
   
       3 . The tool of  claim 1 , wherein the module comprises an electronic board or circuits. 
   
   
       4 . The tool of  claim 1 , wherein electroactive polymeric material changes its state depending on the intensity and/or direction of the vibrations or shock. 
   
   
       5 . The tool of  claim 4 , further comprising a control circuit to control a state of the electroactive polymeric material. 
   
   
       6 . The tool of  claim 5 , wherein the control circuit includes one or more vibration sensors. 
   
   
       7 . The tool of  claim 5 , wherein the control circuit is programmed to apply a voltage or current to the electroactive polymeric material. 
   
   
       8 . The tool of  claim 1 , including a circuit to convert deformation of the electroactive polymeric material into electrical energy and store said electric energy. 
   
   
       9 . The tool of  claim 8 , further comprising a control circuit to use the stored energy to drive the one or more transducers. 
   
   
       10 . A method for reducing the effects of accelerations on a module within a downhole tool, comprising the step of coupling said module to remaining parts of the tool with one or more transducers comprising electroactive polymeric material; and lowering said tool into a subterranean wellbore. 
   
   
       11 . The method of  claim 10 , further comprising the step of changing the state of the electroactive polymeric material depending on the intensity and/or direction of the accelerations. 
   
   
       12 . The method of  claim 11 , further comprising the step of controlling the current or voltage applied to the electroactive polymeric material in dependence of tool accelerations as measured by sensors. 
   
   
       13 . The method of  claim 10 , wherein deformation of the electroactive polymeric material is used to harvest energy from the mechanical vibrations. 
   
   
       14 . The method of  claim 13 , wherein at least part of the energy required to activate the one or more transducers is obtained by the harvesting from mechanical vibrations.